Steel plate bending apparatus

ABSTRACT

A steel plate bending apparatus so constructed that, when an end bending of the steel plate is required, the steel plate is inserted between an upper roll and a pair of lower rolls, the top roll being predeterminedly positioned in a movable manner with respect to the bottom rolls, so that the end bending of the steel plate may be effected in a single operation without reinserting again the steel plate.

U mite States Patent Mori [451 Sept. 26, 1972 [5 STEEL PLATE BENDING APPARATUS 2,995,171 8/1961 Hausler 72/175 X Inventor: M n i i, l v No ak 3, Savory x W k h, W z g l akayama ken Primary Examiner-Mi1t0n S. Mehr Att0rny-Clario Ceccon [22] Filed: June 3, 1971 21 Appl. No.: 149,440 [57] ABSTRACT A steel plate bending apparatus so constructed that, [52] U S Cl 72/173 72/]75 72/35 when an end bending of the steel plate is required, the [51] d 5/14 steel plate is inserted between an upper roll and a pair [58] Fie'ld 173 175 of lower rolls, the top roll being predeterminedly positioned in a movable manner with respect to the bottom rolls, so that the end bending of the steel plate [56] References Cited may be effected in a single operation without reinsert- UNITED STATES PATENTS ing again the Steel p 2,948,323 8/1960 Kerr ...72/l75 X 3 Claims, 6 Drawing Figures PATENTED EP Z Ian 7 I 3 e93 391 SHEET 1 0F 2 FIG.

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STEEL PLATE BENDING APPARATUS BACKGROUND OF THE INVENTION The present invention relates to a steel plate bending apparatus and particularly to an apparatus in which, when the steel plate is subjected to a bending operation into a cylinder, the bending at the extreme end may be performed with ease to result in a cylindrical shape with a true circular section.

In conventional steel plate bending apparatus, when a rolling apparatus other-than a pinch roll apparatus is employed, if the thickness of the steel plate is limited, then the end bending of the plate becomes practically impossible because of the slippage occurring between the rolls. On the other hand, when a pinch roll apparatus is employed, only end bending on one single side of the steel plate is possible and bending of the other end of the steel plate, requires the withdrawal of the plate from the rolls and the subsequent reinsertion thereof between the rolls.

SUMMARY OF THE INVENTION In the apparatus of the present invention, the steel plate is inserted between a top roll and a pair of bottom rolls and the top roll is fixed in a movable manner relative to the pair of bottom rolls, thus permitting'bending of both extreme ends of the steel plate in a single operation and without reinsertion of the steel plate between the rolls.

It is therefore the primary object of the present invention to overcome the disadvantages of the prior conventional rolling apparatus and to provide for the end bending of both ends of the steel plate in a single operation and, taking advantage of the displacement ability of the top roll in a vertical as well as horizontal direction, to provide an improved steel plate bending apparatus suitable for use in wide applications without roll slippage, regardless of the thickness of the steel plate being processed.

It is another object of this invention, to utilize the insertion of the steel plate between a top roll and a pair of bottom rolls and to allow the toproll to be fixed in a movable manner relative to the bottom rolls, so as to perform with ease the end bending of the steel plate and consequently, to manufacture a cylindrical shape with a true circular section without leaving any flattened portion on the periphery of the steel plate and, further, to eliminate such material losses caused by severance of the flattened portion of the steel plate as it was the case with conventional steel plate forming operation.

THE DRAWINGS These and other objects of the present invention will become apparent from the following detailed description thereof with reference to the attached drawings in which:

FIG. 1 is an elevational front view of a steel bending apparatus embodying the present invention;

FIG. 2 is an elevational side view of the aforesaid apparatus represented in FIG. 1;

FIG. 3 is an illustrative and perspective view of the aforesaid apparatus of FIG. 1; and FIGS. 4, 5 and 6 are side views representing the various operations of the bending rolls.

DETAILED DESCRIPTION OF THE INVENTION With particular reference to FIG. 3, reference numerals l and 2 represent a pair of bottom rolls supported horizontally and parallel to each other by a base stand 3. Rolls 1 and 2 are positioned at a predetermined distance from each other and are driven in the same direction by a main electric motor 5 through a group of gear wheels 4.

A top roll 6 is supported by a pair of supporting stands 7 located on opposite lefthand and righthand sides and so arranged that they are capable of being displaced in a horizontal direction along the base stand 3.

A pair of journal supports 8 are mounted on the stands 7 in such a way that they can be displaced in a vertical direction along the supporting stands 7. Journal supports 8 are also connected with piston rods 10 which are connected to the pistons provided in lifting and lowering cylinders 9 incorporated in the supporting stands 7. The lifting and lowering takes place in accordance with the hydraulic pressure existing in the lifting and lowering cylinder 9. On the other hand, the horizontal displacement of the supporting stands 7 is performed by the rotation of threaded spindles 12 provided in the base stand 3. That is to say, feed screws 12 provided with worm wheels 13 at their extreme end are mounted on base stand 3 and are engaged with female threads 14 formed in a portion of the supporting stand 7. Shaft 15 is provided to rotate the feed screws 12 and is supported by brackets 16 protruding from a portion of the base stand 3.. Shaft 15 is driven by an electric motor 19 through chain 17 and chain wheel 18. On both ends of shaft 15 there are fixed worms 20 which are in engagement with the above mentioned worm wheels 13. With the above mentioned arrangement, by rotating the shaft 15, the feed screws 12 are made to rotate in the same direction, allowing the supporting stands 7 to be displaced forward and backward.

The movements of the top roll in the upward and downward directions are caused, as mentioned above, by the vertical movements of the pistons in the cylinders 9. Turning now to FIG. 1, the pressure supply lines 21, actuate the pistons in the downward direction, while the pressure supply lines 22 actuate them in the upward direction. These supply lines are connected to a pressurized-liquid pump by way of a conventional changeover valve (not shown).

The top roll 6 is provided with a mechanism which serves to indicate the horizontal position of the roll, that is to say, on the bearings 8 there are provided at both ends of the top roll 6 in individual blocks the pistons 23, these pistons 23 being inserted from the bottom into cylinders 24 of the supporting stands 7.

Further, inside cylinders 24, in a space above the pistons 23 there is contained the liquid which is connected fluidly with the indicating lines 25 separately provided to keep the same level. With this arrangement, by comparing the level in each individual indicating line 25, it is possible to detect a difference in height between the two individual bearings 8, that is to say, to detect the accuracy of the horizontal setting of the top roll 6 and to carry out the necessary microadjustments in the steel plate bending operation.

By having the indicating lines 25 with a diameter smaller than that of cylinders 24, it is possible to magnishown in FIG. 4, to press on and bend the extreme end portion of the steel plate a. The flow of the pressurized liquid is then switched to supply lines 22 to allow the top roll 6 to be raised. With the steel plate shifted to the left, as shown in FIG. 5, the electric motor 19 is driven in the reverse direction and the top roll 6 is displaced to the right and lowered under pressure to effect the bending of the steel plate a on its opposite side, as shown in FIG. 5. Subsequently the top roll 6 is posi tioned between bottom rolls 1 and 2, as shown in FIG. 6, and is at the same time lowered; the main driving motor is energized to rotate the bottom rolls 1 and 2 in clockwise and counter-clockwise directions respectively, these revolutions of the rolls bending the steel plate a to form a circular section. The finished and bent steel plate is removed from the rolls by losening one fixing bolt 26 and swinging the supporting stand 7 outwardly using the other fixing bolt 26 as a fulcrum.

What is claimed and is desired to secure by letters patent of The United States is:

l. A steel plate bending apparatus comprising: a pair of lower rolls positioned horizontally and parallel to each other; a base stand supporting said pair of lower rolls; an upper roll capable of free vertical displacement; a pair of terminal supporting stands for said upper roll incorporated on said base stand for displacement of said upper roll above the said lower rolls and in direction parallel with the said lower rolls; means on said base stand to rotate said lower rolls; means for displacing said terminal supporting stands in forward and rearward directions; and hydraulically driven means located on supporting stands to move said upper roll in upward and downward directions.

2. A steel plate bending apparatus as claimed in claim 1, wherein said supporting stands are provided with cylinders having pistons therein, and wherein said upper roll is provided with bearings connected to said pistons, further including a pair of indicating lines in fluid communication with said cylinders to accurately adjust the bending operation of said steel plate by detecting the parallelism of said upper roll.

3. A steel plate bending apparatus as claimed in claim 1, in which said means for displacing said terminal supporting stands in forward and rearward directions is a motion transmitting mechanism which comprises: a pair of feed screws having worm wheels and being located at one extreme end of the said supporting stands; female threaded portions formed in said supporting stands for engagement with said feed screws; an electrically-driven, bracket-supported shaft; and worms fixed to both ends of said shaft and in engagement with said worm wheels of said feed screws. 

1. A steel plate bending apparatus comprising: a pair of lower rolls positioned horizontally and parallel to each other; a base stand supporting said pair of lower rolls; an upper roll capable of free vertical displacement; a pair of terminal supporting stands for said upper roll incorporated on said base stand for displacement of said upper roll above the said lower rolls and in direction parallel with the said lower rolls; means on said base stand to rotate said lower rolls; means for displacing said terminal supporting stands in forward and rearward directions; and hydraulically driven means located on supporting stands to move said upper roll in upward and downward directions.
 2. A steel plate bending apparatus as claimed in claim 1, wherein said supporting stands are provided with cylinders having pistons therein, and wherein said upper roll is provided with bearings connected to said pistons, further including a pair of indicating lines in fluid communication with said cylinders to accurately adjust the bending operation of said steel plate by detecting the parallelism of said upper roll.
 3. A steel plate bending apparatus as claimed in claim 1, in which said means for displacing said terminal supporting stands in forward and rearward directions is a motion transmitting mechanism which comprises: a pair of feed screws having worm wheels and being located at one extreme end of the said supporting stands; female threaded portions formed in said supporting stands for engagement with said feed screws; an electrically-driven, bracket-supported shaft; and worms fixed to both ends of said shaft and in engagement with said worm wheels of said feed screws. 